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Objectives: An unobstructed extracardiac conduit (ECC) is essential for optimal Fontan haemodynamics. We aimed to evaluate the feasibility and results of percutaneous transcatheter stenting of the ECC in paediatric patients with a significant Fontan pathway obstruction., Methods: Our institutional database was searched to identify all Fontan patients who had a stent placed in their ECC. Medical records, cardiac catheterisation data and echocardiographic investigations were reviewed. Vessel diameters were normalised to account for differences in body surface area., Results: Nineteen Fontan patients (age 6.5±3.2 years; male 78.9%) with a significant stenosis of their Dacron ECC graft were identified. Seven patients presented with protein-losing enteropathy (36.8%). An ECC obstruction was suspected on echocardiography in only 6/19 patients (31.6%). The mean minimum diameter of the ECC was 8.3±2.4 mm. A stenosis of >45% was seen in the majority of patients (n=12, 63.1%). Significant correlations between the severity of the ECC obstruction and Fontan pathway vessel diameters were found (all p<0.05). Stenting was successful in all children. The ECC diameter increased significantly after stenting (p<0.0001). An acute clinical benefit of ECC stenting was observed in 18/19 (94.7%) patients. ECC patency was good during a mean follow-up of 1.8±0.9 years., Conclusions: The feasibility and acute results of percutaneous transcatheter ECC stenting are promising and may provide a good alternative to postpone surgery to a later age. The mechanisms contributing to the development of ECC stenoses are likely multifactorial., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: The postnatal development of myofibrillar mechanics, a major determinant of heart function, is unknown in pediatric patients with tetralogy of Fallot and related structural heart defects. We therefore determined the mechanical properties of myofibrils isolated from right ventricular tissue samples from such patients in relation to the developmental changes of the isoforms expression pattern of key sarcomere proteins involved in the contractile process., Methods and Results: Tissue samples from the infundibulum obtained during surgery from 25 patients (age range 15 days to 11 years, median 7 months) were split into half for mechanical investigations and expression analysis of titin, myosin heavy and light chain 1, troponin-T, and troponin-I. Of these proteins, fetal isoforms of only myosin light chain 1 (ALC-1) and troponin-I (ssTnI) were highly expressed in neonates, amounting to, respectively, 40% and 80%, while the other proteins had switched to the adult isoforms before or around birth. ALC-1 and ssTnI expression subsequently declined monoexponentially with a halftime of 4.3 and 5.8 months, respectively. Coincident with the expression of ssTnI, Ca(2+) sensitivity of contraction was high in neonates and subsequently declined in parallel with the decline in ssTnI expression. Passive tension positively correlated with Ca(2+) sensitivity but not with titin expression. Contraction kinetics, maximal Ca(2+)-activated force, and the fast phase of the biphasic relaxation positively correlated with the expression of ALC-1., Conclusions: The developmental changes in myofibrillar biomechanics can be ascribed to fetal-to-adult isoform transition of key sarcomeric proteins, which evolves regardless of the specific congenital cardiac malformations in our pediatric patients., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Little is known about the outcome of acute thrombotic occlusion of segments of the cavopulmonary connections (CPC) in infants and children with univentricular hearts. Early recognition and aggressive therapy may result in successful salvage of some of these patients. Five consecutive patients (age range 4-8 months) presenting with acute occlusion of a CPC segment underwent emergency cardiac catheterization. After angiographic confirmation, the occluded segment was crossed using an endhole catheter and guidewire combination. Serial balloon dilation and stent implantation (ten stents in total) were undertaken to recanalize the occlusion. The stents used were mounted on balloons ranging in diameter from 6 mm to 8 mm, depending on the size of the native vessel. The sites of occlusion were the left pulmonary artery (n=4), and the left-sided superior caval vein (n=3). All occlusions could be successfully recanalized. In three patients, early reocclusion necessitated either surgery or repeat catheterization and angioplasty. There were two early deaths, due to recurrent thrombotic obstruction confirmed either at autopsy or angiography. The remaining patients are alive and well; the majority of survivors have undergone completion of the Fontan operation. A high index of clinical suspicion combined with aggressive therapy can result in successful recanalization in some infants with acutely occluded CPC segments, with acceptable long-term outcome.

Objectives: To investigate the impact of prenatal detection of congenital heart disease on preventing severe preoperative lactacidosis., Design: Patients operated upon for congenital heart disease during the first 31 days of life (n = 209) were studied retrospectively, 21 were diagnosed prenatally and 188 patients had not been diagnosed prenatally. Preoperative lactate, pH and base excess were evaluated., Results: Differences were noted in preoperative pH (7.28 +/- 0.03 vs. 7.24 +/- 0.01, P = 0.29), base excess (-5.83 +/- 0.64 vs. -6.93 +/- 0.46 mmol/L, P = 0.10) and lactate (3.05 +/- 0.35 vs. 6.08 +/- 0.45 mmol/L, P < 0.001), indicating a significant difference in blood lactate values in favor of the prenatally diagnosed group., Conclusions: Prenatal diagnosis of congenital heart disease and the resulting immediate postnatal care prevent lactate increase in the preoperative period of these patients. This may decrease the risk of cerebral damage and result in the patient being in better condition at surgery.

Objectives: Congenital heart disease is the leading cause of death in the first year after birth. Prenatal diagnosis of the disease can optimize the preoperative condition of the patient and may help in the prevention of acidosis. In this retrospective study we compared the occurrence of metabolic acidosis in patients with and without prenatal diagnosis of a congenital heart disease., Methods: Data of 408 patients who needed an operation for congenital heart disease within 31 days of life were analyzed retrospectively. Arterial blood gases at fixed time intervals and worst blood gas of 81 patients with and 327 patients without a prenatal diagnosis were compared, categorizing the patients on ductus dependency, anticipated univentricular or biventricular repair, and left-sided, right-sided, or no heart obstruction., Results: In the overall group significant differences in lowest pH, lowest base excess, and highest lactate level were found, with metabolic acidosis more common among the patients with a postnatal diagnosis. In the group of patients with ductus-dependent congenital heart disease, the difference between patients receiving a prenatal and those receiving a postnatal diagnosis was more significant than in the group with non-ductus-dependent lesions. Analyzing patients with right-sided, left-sided, and no obstruction separately, significant differences were found in the group with left-sided heart obstruction for lowest pH and base excess and in the group with right-sided heart obstruction for lowest base excess., Conclusions: Prenatal diagnosis of congenital heart disease minimizes metabolic acidosis in patients with congenital heart disease and may be associated with improved long-term outcome and prevention of cerebral damage among this fragile group of patients, although no significant effect on direct surgical outcome was encountered.